Magnetic core assembly



Feb. 11, 1958 J. P. JONES MAGNETIC CORE ASSEMBLY 2 Sheets-Sheet 1 FiledMay 20, 1955 INVENTOR.

JOHN B41/L JONES Feb. 11, 1958 J. P. JONES 2,823,360

I MAGNETIC CORE ASSEMBLY v Filed May 20, 1955 2 Sheets Sheet 2 INVENTOR.JOf/A/ P401. (DA/E6 AGENT United States Patent lvIAGNETIC Conn ASSEMBLYJohn Paul Jones, Pottstown, Pa., assignor to Burroughs Corporation,Detroit, Mich., a corporation of Michigan Application May 20, 1955,Serial No. 509,855

9 Claims. (Cl. 336-65) The present invention relates to circuitassemblies and more particularly to the assembly of magnetic cores upona terminal board while in association with a plurality of electricalcircuits, and is an improvement upon the magnetic core mounting assemblydescribed and claimed in applicants pending application Serial No.472,135, filed November 30, 1954.

In assemblies of the type to which the invention relates, it hasheretofore been the practice to mount a plurality of core assembliesupon a single terminal board or panel of insulating material and becauseof the size of the board and the inaccessibility of the cores on theboard, it is dihicult if not impossible to apply windings to the coresby means of an automatic core winding machine. It therefore becomesnecessary to wind the cores by hand weaving techniques which involvesthe use of a needle-shaped shuttle-bobbin. An operator winding the coresmust first wind wire on the shuttle, then, by threading the shuttlethrough the core center, Wrap the turns of the windings on one at atime. Since a single board takes from eight to twelve manhours to wind,the lost time becomes a vital factor in production costs.

Further the boards in present day use have long transverse wires whichrun the length of the board from a socket at the end, so theconglomeration of wires adds to the chances for error and confusion.Also, it will be seen that, the arrangement of components on either sideof the board makes the unit unadaptable to dipsoldering techniques.

Another objectionable feature of such prior package is that the entireweight of the unit is exerted upon the socket connector and so there isa tendency to loosen the socket contacts and in time will cause saggingof the board or package.

A further disadvantage to a single board or unitary package is thattrouble in one of its components due to mistakes in wiring or otherwiserequires the entire package to be discarded.

An object of the present invention is to provide an improved package formagnetic core assemblies or the like.

Another object is to provide a printed wiring card package wherein aplurality of separate components are so interconnected as a completeassembly that any component can be readily removed and replaced.

Another object is to provide a magnetic core assembly wherein the corescan be wound by automatic winding machines.

A further object is to provide a card and receptacle system of assemblywherein the herebefore old arrangement of transverse wiring isminimized.

A still further object is to present a technique for the manufacture ofindividual module bits, which, when assembled into a specific grouping,will perform logical functions. For example, a particular groupedassembly might be put together to make a shift register, or a 2,823,360Patented Feb. 11, 1958 counter, or any other logical function that mightbe desired.

In the accompanying drawings,

Figure 1 is a perspective view of a magnetic core supporting structure,such as a board, card or panel of insulating material, forming a wiredcomponent of a core assembly of the invention and showing one face ofthe board;

Figure 2 is a section on line 22 of Figure 1;

Figure 3 is a perspective view of the same showing the opposite face ofthe board;

Figure 4 is a face view of a complete assembly of components of the typeshown in Figures 1 and 3 and showing one board released for replacement;

Figure 5 is a fragmentary detail, on a larger scale, of the assemblyshowing the interconnecting means for one end of the components;

Figure 6 is a fragmentary detail, on the same enlarged scale, showinggenerally the wiring thereon;

Figure 7 is a showing of the opposite face of the board shown in Figure6;

Figure 8 is a perspective, partly broken away, of a complete assembly asa housed unit.

Referring to Figures 1 and 3 of the drawings, a single component isshown as representing any one of the components in an assembled package,and comprises a dielectric board or card 10 exhibiting a strip-likeconfiguration and of rigid insulating material having holes 11therethrough for respectively mounting magnetic toroid cores 12, as wellas forming a base for circuit wiring. In the preferred form the wiringis of the printed conductor pattern type, such pattern being formed bycopper laminated phenolic photo-sensitized, exposed through a negativehaving the desired configuration, developed and etched, thereby havingon the board the proper conductor pattern. The cores 12, prior towinding, are cemented in place upon the board 10 respec tivelyconcentrically arranged with respect to the holes 11, namely with theinside diameters of the cores placed in direct axial alinement with thematching holes 11.

In order to permit easy winding of the cores 12, but more particularlyto make automatic winding possible, the card or board in is formed witha narrow dimension in one direction, having as shown a width slightlygreater than the outer diameter of the cores 12. The board 10 isprovided, at two opposite edges of each core location, with notches 13in close proximity to its adjacently mounted core 12 and preferablyarced with the same radius of curvature as that of the periphery of thecore. Thus a winding can be made through the two closely located notchesto encircle the core on opposite sides thereof while also passingthrough a board hole 11, which arrangement makes possible ready windingby automatic winding machines.

Illustratively the strip or the board 10 is shown on face 14 as wiredfor two cores 12 and diode components 15, while the printed Wiring 16extends over the surface of the board. Some of the wiring 16 terminatesat one end of the strip for plug-in relation to a socket connectingpanel 17, which receives the terminal ends of all of the strips whenassembled as a package. The opposite face 13 of the strip or board 10 islikewise provided with associated printed wiring 21 for proper circuitryand terminates as described for wiring 16 in terminals to enter thesocket panel 17. The end of the board it opposite to the terminal end,has a projecting lug or key 19 for associating with a cover member aswill be later explained.

The socket panel 17 has a slot 22 longitudinally disposed to receive andseat the terminals or contact ends of the boards or strips 10 andestablish circuitry connecting means through pairs of spring contactors23 in the slot 22 of the panel 1'7. For the particular circuits hereshown, three such contactors for each board are mounted transversely inthe slot 22 and arranged respectively for spring pressed contact withthe related conductors 16 and 21 on the respective faces of each board10. These contactors project beyond one side of the panel 17 to provide,in an assembled package, a row of lugs 24 for soldering connections orplug-in sockets.

For board and circuit connection between abutting strips or boards toform a unitary package, certain terminals of the wiring 16 terminate atone or both side edges of the board, the arrangement being such thatconductors on the respective adjacent boards align and abut each other.Thus when one board abuts an adjacent board in edge to edge relation,the two meeting conductors may be conductively coupled by a dab 25 ofsolder to thereby complete not only an electrical connection, but alsoto lock the two boards together in coplanar relationship. In thismanner, a large number of strips 10 may be assembled in side-by-siderelationship and locked together to form a composite printed wiringpanel. A panel in the process of being built-up in this manner is shownin Figure 4. In the event of malfunction, instead of requiringreplacement of the entire panel the component strip containing thefaulty element may be easily separated from the balance of the panel andreplaced by a correctly functioning strip. The strip It) may be easilyseparated by softening the soldered connections 25 and reformed into anew panel by resoldering the original connections.

When a package is completed, as shown in Figure 4, it is preferable toenclose it in a cover 26 with the panel 17 as a base to which the cover26 is attached by suitable fastening means. The top of the cover 26 isprovided with a row of slots 27 corresponding in number to the number ofcomponents 1%, such slots 27 being dimensioned to snugly seat therespective projecting end lugs 19. The unitary assembly of cover andbase thus becomes a rigid retaining frame for the core components,besides being an efiective dust protector and shield against injury.

It will now be apparent that a complete unitary supporting structure formagnetic cores and circuits has i been devised in the form of a package,made up of a plurality of individual strips or boards attached togetherin edge to edge relation in conductively coupled rel"- tion to form aunit, such attaching means being detachable for the release of anyindividual board for repair or replacement. Further the novel conductorassembly, with its bonding medium, reduces transverse wiring to aminimum. Also it will be seen that the number of boards to make up apackage can be varied to meet ,1

difierent conditions including the use of boards having differentcircuits and cores as substitutes for any board where necessary. Suchchanges are possible by merely unsoldering the bonding medium betweenselected boards. It will also be seen that the relatively large notchesbounding opposite sides of a magnetic core provides easy access to thecores for winding by automatic means, thereby eliminating the usual handwinding of the relatively miniature core.

What is claimed is:

l. A supporting structure for package mounting of toroidal magneticcores comprising a board of dielectric material, having parallelopposite side portions, each of said side portions being provided withan indentation, said indentations being oppositely aligned and togetherform a spaced apart pair between which said board is provided with anaperture, a toroidal magnetic core disposed on said board between saidpair of indentations, with the bore of the core in axial alignment withsaid aperture and windings threaded through said core, said aperture,and around said indentations so as to bind said core to said board.

2. A supporting structure for package mounting of magnetic cores andelectrical circuits, comprising a plurality of individual boards ofnonmagnetic, dielectric material, arranged side by side for edge to edgecontact, conductors on at least one face of each board terminating in analigned abutting relation with the respective conductors of an adjacentboard, each one of said boards having edge notches located at oppositesides thereof together forming an aligned pair, the area between saidnotches being provided With an aperture, and a toroidal magnetic coredisposed on each of said boards, with the bore of the core axiallyaligned with the aperture, windings threaded through said core, saidaperture and around one of said notches to bind said core to said board,a conducting medium bonding the abutting conductors, together to formsaid boards into a rigid assembly, a base to support said rigidassembly, and a cover member secured to said base and cooperatingtherewith to enclose said assembly.

3. A supporting structure for package mounting of toroidal magneticcores and electrical circuits, comprising a plurality of boards ofnon-magnetic dielectric material, arranged side by side for edge to edgecontact, conductors on at least one face of each board having a terminalportion aligned in abutting relation with the respective terminalportion of a conductor on an adjacent board, each of said dielectricboards being provided with a plurality of edge notches and being furtherprovided with an aperture adjacent said notches, a toroidal magneticcore disposed on at least one of said boards, the bore of the core beingaxially aligned with the aperture of said board, windings extendingthrough said core, said aperture, and around one of said notches, and aconducting medium bonding the abutted conductors together, whereby theboards form a complete rigid package from which any board can be removedby breaking the bond therebetween.

4. A supporting structure in accordance with claim 3, wherein anelectrical insulating socket panel is adapted to receive aligned boardends in interfitting relation, and electrical conductive contactorsbeing carried by said panel for respectively engaging the conductors onthe board.

5. The combination, according to claim 4, wherein an opposite end ofeach board is provided with a projecting lug, and wherein a cover isprovided for housing said assembly, said-cover being provided with slotsto engage said lugs so as to align the boards within the cover and forma rigid, closed unit.

6. A supporting structure for package mounting of toroidal magneticcores comprising a plurality of narrow finger-like fiat boards ofnon-magnetic dielectric material having parallel opposite side portions,at least one of said side portions being provided with an identation,each of said boards being provided with an aperture adjacent to saidindentation, a toroidal magnetic core disposed on each of said boardswith the bore of the core in alignment with said aperture, and windingsrunning through said core, said aperture, and around said indentation tobind said core to said boards, said boards being arranged side by sidefor edge-to-edge contact, and electrical conductors on at least one faceof each board, certain of said conductors having terminals in alignedabutting relation with respective conductors of an adjacent board. 7

7. A supporting structure for package mounting of electrical circuitscomprising, a plurality of thin, elongated, finger-like flat strips ofelectrically insulating, nonmagnetizable material, said strips beingmounted in edge abutting relationship and in the same plane forming acomposite board, each of said strips being provided with a plurality ofapertures extending therethrough, toroidal magnetic cores disposed onone side of each of said strips with the bore of each core in axialalignment with a respective one of said apertures, said strips having atransverse dimension approximately equivalent to the diameter of saidmagnetic core, electrical conductors on opposite faces of each of saidstrips, certain of the conductors on one strip contacting conductors onan adjacent strip thereby forming electrical wiring extending from onestrip to another, said contacting conductors being connected byfrangible connections for ready separation for replacement of individualstrips, and means on said cores connecting said cores to said electricalconductors.

8. A supporting structure for package mounting of electrical circuitscomprising, a plurality of individual fiat strips of dielectricnon-magnetic material, said strips being arranged side by side for edgeto edge contact, each of the strips being provided with at least twoapertures extending therethrough, toroidal magnetic cores disposed onone surface of each of said strips and projecting away therefrom withthe axes of the cores extending perpendicular to the plane of thestrips, the bore of each core being in alignment with a respective oneof said apertures, electrical conductors disposed on opposite surfacesof each of said strips, certain of said conductors terminating inaligned abutting relation with conductors of an adjacent strip, otherconductors on said strips terminating at a free edge thereof, electricalwindings on the cores, said windings being provided with leads, at leastcertain of said leads passing through said apertures, and terminalsdisposed on opposite faces of said strips, said leads being fixed to theterminals on the opposite sides of the strips from which the coresproject.

9. A supporting structure for package mounting of electrical circuitscomprising, a plurality of narrow, flat strips of non-magneticdielectric material, said strips being arranged side by side for edge toedge contact, each of said strips being provided with a plurality ofapertures extending completely therethrough, toroidal magnetic coresdisposed on one side of said strips and projecting away therefrom, thebore of each core being disposed in alignment with a respective one ofsaid apertures, electrical conductors disposed on opposite faces of eachof said strips, certain of said conductors terminating in alignedabutting relation with conductors of an adjacent strip, and otherconductors on said strips terminating at a free edge thereof, andwindings on said cores with leads from certain of the windings passingthrough said apertures to certain of the electrical conductors on theopposite face of the strip from which the cores project.

References Cited in the file of this patent UNITED STATES PATENTS2,014,524 Franz Sept. 17, 1935 2,611,807 Lazzery Sept. 23, 19522,700,150 Wales Jan. 18, 1955 2,706,697 Eisler Apr. 19, 1955 2,719,965Person Oct. 4, 1955 OTHER REFERENCES Printed Unit Assemblies forTVTele-Tech.-June 1952, pp. 38-40, 112, 114, 116, 118, 120 (particularlyp. 40).

Etched Circuits-Wireless World, December 1952, page 488.

